Definition & calculation
Numerator: Number of people in the target population with reliable access to a sufficient quantity of safe water (meeting agreed minimum quantity and quality standards) at time of assessment
Denominator: Total number of people in the target population
Divide the number of people whose water source meets agreed safe-water criteria (quantity, quality, proximity/access) by the total target population, verified through household survey combined with source-level checks.
Formula: (Numerator ÷ Denominator) × 100
Means of verification
Household survey, water point mapping, water quality tests
Interpretation
Direction: Higher is better
Typical reporting frequency: Baseline, midline and endline (or annual)
Guidance & common pitfalls
Combines quantity, quality and accessibility; do not equate 'improved source' with 'safe water', as contamination and distance can undermine safety.
This library is a curated reference to adapt, aligned generically with recognised humanitarian frameworks (Sphere, cluster registries, IASC, CHS and others). It is not an official indicator registry — always use the exact indicator definitions your donor or cluster requires.
Related indicators
- Incidence of diarrhoeal disease among children under five in the target area
- % of households with access to and use of sufficient soap and essential hygiene items
- % of sampled water points / household stored-water samples meeting agreed safety standards (0 CFU E. coli / adequate free residual chlorine)
- % of target community members who can identify at least one functioning channel to give feedback or raise a complaint about WASH services